Kenneth Baker, now Lord Baker, introduced the National Curriculum and early versions of academies when he was Education Secretary under Margaret Thatcher from 1986 to 1989.

But last night he spoke out against plans put forward by current Education Secretary Nicky Morgan to force all schools into academies – arguing they should make the transition at their own pace.

His intervention is a further sign of unease in the Conservative Party over the policy, and in a Commons debate on Wednesday numerous Tory MPs raised concerns.

On BBC Newsnight, Lord Baker said he supported academies and the huge growth in their number in recent years, but added: “There’s been a huge change which has happened naturally and I think that’s the best way to proceed quite honestly.”

Former schools minister Tim Loughton said: “As a Conservative I always believe in choice. Can she outline to me the downside of schools migrating organically to academy status rather than imposing a compulsory and arbitrary timeline on them?”

Dorset MP Richard Drax told the House: “Can I suggest caution. A natural progression from one to another would probably be the best way to go rather than imposition.”